Devices are increasingly incorporating multiple types of functionality, each having varying types of controls. Touch sensitive input panels are similarly being more widely implemented to support a user's interaction with many types of hand-held devices relative to at least some of the multiple types of incorporated functionality. In order to maximize screen size, while limiting the overall dimension of the device, many of these devices incorporate the touch sensitive panels in conjunction with a display, where the user interaction with the touch panel is supported with visual prompts and feedback, and/or the user is interacting with elements being displayed on the screen. However many implementations of touch sensitive panels, used in conjunction with a display involve a user interacting with the touch sensitive panels, which can obstruct at least partially the user's view of the screen, and the elements on the screen with which the user is attempting to interact. Furthermore, interaction with the display with ones fingers can often leave smudges, which while they do not generally affect the operation of the device, can sometimes affect the appearance of the device, and may also impact the perceived image quality.
Some devices have attempted to relocate the touch sensitive input panel on the back side of the device, in order to avoid some of the downside associated with interacting with the device using the same surface shared with the display. However, in some implementations it is not always clear which elements on the screen that the user might be engaging. Some embodiments, have attempted to compensate, by superimposing a visual representation of the current position of pointing device such as a finger as it slides across the touch sensitive input panel located on the rear of the device. However, this generally requires that the finger remain in relative proximity to the back of the device, while being tracked and that might limit the available interactions for other activities.
Furthermore, many types of touch sensitive input panel implementations are limited to providing a single location value associated with interacting with the input panel regardless as to whether a single position or multiple positions on the input panel are being engaged. In some instances, when multiple positions are simultaneously engaged, an averaging of the actual positions may be reported to an input controller, which in some circumstances may be misleading and/or misinterpreted by the device. As a result, it may be difficult to track the position of multiple pointing objects, such as a user's multiple fingers, and/or it may affect the accuracy of the reported position.
Consequently, the present inventors have recognized that it would be beneficial if an effective control scheme could be implemented that makes use of a single pointer for interacting with a touch sensitive user interface, which would readily allow the user to interact with the device via multiple controllable interface functions that can be readily accessed.